WDM network traffic grooming using clusters

The emergence of wavelength division multiplexing (WDM) technology has led to a tremendous increase in the available transmission capacity in wide area network (WAN). This technology is also being used in backbone networks. For a large-scale network, it is difficult to maintain the centralized global state information of the network. Hence, distributed methods are required to organize network nodes and to handle the information in a more localized manner. In this paper we present a method to overcome this problem using a hierarchical structure of node clusters for traffic grooming that provide scalable, efficient and cost-effective WDM optical network. When applying the hierarchical structure network is decomposed into clusters of different hierarchical levels. At the first level one node in each cluster is designated as hub, master node or cluster head for traffic grooming. At the second level of hierarchy few selected hubs, master nodes or cluster heads from the first level forms another cluster for grooming inter-cluster traffic. Again one or a number of nodes at the second level of hierarchy is designated as hub, master node, or cluster head for control and management of the network. All other nodes on the network are known as member nodes. We have focused at the second level of hierarchy in our paper and propose a model for traffic grooming based on cycles over the clusters to maintain the traffic on the network when a link or links are broken between clusters.